1. Field of the Invention
The present invention relates to a musical apparatus and a method for imparting tone effects to the musical tones which are produced based on the music performance data signals including tone effect control data, and a computer program for realizing such an apparatus and a method using a computer system, and more particularly to an apparatus and a method in which some tone effect control data to determine tone effects which are equipped or provided in a musical apparatus of a complicated model and not in a musical apparatus of a simplified model may be utilized via conversion to provide similar surrogate tone effects in such a musical apparatus of a simplified model.
2. Description of the Prior Art
In the field of electronic musical tone producing apparatuses, tone properties such as tone pitches, tone colors and tone effects of the tones to be produced are controlled or determined by music performance data signals, generally, under the MIDI protocol. In the MIDI protocol, however, the controls of the tone effects are not defined universally in the basic MIDI format, and consequently, such control data or messages are defined locally or individually according to the respective manufactures' definitions in the data clauses prepared as the exclusive messages. There are various ranks of tone producing apparatuses under the MIDI protocol, from a low-end model incorporating a few kinds of tone effects to a high-end model incorporating many kinds of tone effects in view of the grade of tone effects. Accordingly, the MIDI control data, i.e. MIDI messages may not necessarily be compatible among different ranks of tone producing apparatuses, or among apparatuses manufactured by different manufactures even of a similar rank, or among apparatuses manufactured in different years or in different specifications even by the same manufacture. Thus, the same MIDI performance data string may not necessarily give an identical music performance with the identical tone effects.
In order to solve such disadvantages, an idea is proposed and disclosed in the specification of a published Japanese patent application under the unexamined publication No. H8-87270, wherein the music performance data on the tone pitches, the tone colors and the tone effects as prepared for a higher-rank model are converted into the data for the tone effects which are available for the tone production on a lower-rank model. In other words, on a lower-rank model not incorporating some particular tone effects which are equipped in a high-rank model, such particular tone effects are surrogated by similar tone effects available in the lower-rank model.
In the above referenced idea, the system exclusive message codes or the like are used to designate the intended tone effects. The system exclusive message code includes and effect selection code for designating a category or type of effect, and effect control parameter code for designating a parameter to be controlled, and effect parameter value determining data for determining the value of the designated parameter, thereby controlling a specific operation of the tone effect imparting algorithm to realize an intended tone effect in the digital signal processor. In the standard MIDI protocol, the effect category is represented by two bytes of data, in which the most significant byte (MSB) represents a rough effect category (hereinafter referred to as TYPEMSB in the list) and the least significant byte (LSB) represents a precise effect category or effect variation (hereinafter referred to as TYPELSB in the list). The effect variations which are assigned to the TYPELSB code of “00H” for the respective rough categories are referred to as “fundamental effects.” The alphanumeric notation ended with a character “H” such as “00H” and “FFH” represent numeral values in hexadecimal notation. For each specific effect as assigned to each effect variation (including fundamental), there are sixteen parameter items numbered from “1” through “16” and constituting a set of sixteen parameter values (represented by 16-byte data in total), although some may be absent depending on the tone effects. The contents of the sixteen parameter items as well as the sixteen parameter values are not necessarily the same for all the effect categories, but may be different from one category to another.
The effects can be listed in an assigned effect list described in a matrix form placing the MSBs (rough categories) vertically to define rows and the LSBs (variations) horizontally to define columns. FIG. 3 is an assigned effect list describing the assigned effects on a high-end model in detail including variation effects, while FIG. 4 is an assigned effect list describing the assigned effects on a conventional low-priced model in detail including variation effects. Whereas a high-end model has effects assigned to the TYPEMSB code “51H” and above, a low-priced model does not have effects assigned to such a range of TYPEMSB codes. Among variations for the same rough category, the variation effects are controlled by using effect control parameters which are compatible with the fundamental effect. For example, effect control parameters for the rough category of TYPEMSB=4EH, are shown in FIGS. 6 and 7, respectively, in which FIG. 6 describes the effect control parameters for the “AUTO WAH” effect under TYPELSB=00H, and FIG. 7 describes the effect control parameters for the “AUTO WAH+DISTORTION” effect under TYPELSB=01H and those for the “AUTO WAH+OVERDRIVE” effect under, TYPELSB=02H.
FIGS. 6 and 7 describe, from left column to right, parameter Nos., parameter names, displayed value ranges, parameter value ranges, etc. The parameters for “AUTO WAH” effect are “LFO Frequency,” “LFO Depth,” “Cutoff Frequency Offset,” “Resonance,” “EQ Low Frequency,” “EQ Low Gain,” “EQ High Frequency,” “EQ High Gain,” “Dry/Wet Balance” and “Drive.” The parameters for “AUTO WAH+DISTORTION” and for “AUTO WAH+OVERDRIVE” are the same as those for the above-mentioned “AUTO WAH” plus “EQ Low Gain (distortion),” “EQ Mid Gain (distortion),” “LPF Cutoff” and “Output Level.” Under such provision of the parameters, therefore, an apparatus not equipped with “AUTO WAH+DISTORTION” effect or “AUTO WAH+OVERDRIVE” effect can produce musical tones with similar tone effects by surrogating (i.e. utilizing) the fundamental effect “AUTO WAH” for (i.e. in place of) such a variation effect, thereby providing better reproduceability of the music performance than the case employing no such absent (non-equipped) effects.
Among various kinds of models, different effects are equipped on different models, and some model may be equipped with no effects assigned to particular categories. For example, comparing FIG. 3 and FIG. 4, it will be understood that where a music performance data string composed for the high-end model (FIG. 4) and having effect control data for “2WAY ROTARY SPEAKER” effect of TYPEMSB=56H is played back on the low-priced model (FIG. 3), the produced tones of the played-back music performance carry no effect, as no effect is assigned at the effect code of TYPEMSB=56H, which frame says “(NO EFFECT OR THRU).” Likewise at the effect codes of TYPEMSB=51H, 52H, 53H, 57H, 62H and 63H, no effects are imparted to the tones produced on the low-priced model. In the assigned effect lists, the effect code frame having a description of “NO EFFECT OR THRU” means that there is no effect assigned to the frame, and the effect code frame under TYPELSB=01H and TYPELSB=02H column marked with shading means the same effect as the fundamental effect under TYPELSB=00H is assigned to the frame, i.e. the effect for the frame “01H” and the frame “02H” is substituted by the effect for the frame “00H.” The “ROTARY SPEAKER” effect is an electronic simulation of a mechanical rotary speaker of which the rotating speed is controllable. The “2WAY ROTARY SPEAKER” effect is an electronic simulation of two mechanical rotary speakers arranged in parallel.
However, even in the case where the music performance data string includes rough category effect codes for which no effects are assigned on the low-priced model, it will be preferable to utilize some surrogate similar effects assigned to other rough category effect codes. For example, the “2WAY ROTARY SPEAKER” effect at TYPEMSB=56H in FIG. 3 may be substituted (surrogated) by the “ROTARY SPEAKER” effect at TYPEMSB=45H. Similarly, the effects at TYPEMSB=52H, 62H and 63H may preferably be surrogated by other similar effects (such as “AUTO WAH,” “DISTORTION” and “ROTARY SPEAKER”), respectively. In this connection, where effects can be surrogated by other effects beyond categories on a low-priced model, it may be considered that an assigned effect list as shown in FIG. 5 is applicable.
But as a matter of fact, however, the effect control parameters for such a surrogate effect are not the same as the effect control parameters for the original effect, and the surrogation is not necessarily possible. FIGS. 8 and 9 explains such situations with respect to the “2WAY ROTARY SPEAKER” effect and the “ROTARY SPEAKER” effect, showing the assigned effect control parameters to the respective parameter Nos. 1 through 16. Each of the lists indicates, from left to right, the parameter Nos., the parameter names and the ranges of the respective parameter values. The “2WAY ROTARY SPEAKER” effect of FIG. 8 contains parameters “Rotor Speed,” “Drive Low,” “Drive High,” “Low/High Balance” and so forth, while the “ROTARY SPEAKER” effect of FIG. 9 contains parameters “LFO Frequency,” “LFO Depth” and so forth. Thus, if the “ROTARY SPEAKER” effect is set as a surrogate for the “2WAY ROTARY SPEAKER” effect, the parameter No. “2” designates the “LFO Depth” parameter in place of the “Drive Low” parameter, and accordingly the parameter values for the parameter item of “Drive Low” will determine the parameter value for the parameter item of “LFO Depth,” and consequently an effect which is not intended by the user will be imparted to the musical tones to be produced.